X5 E70 Late 2007 completely dead, no electronic sign of life

applekev · Post by **applekev** » Sat Jun 18, 2016 1:45 pm

Hello,

Just wanted to share the experience today and get any thoughts or feedback.

I had a replacement battery fitted around 6 months ago, from a BMW specialist and had no problems since. Then after a short run this morning and an hour later I went to get in and the doors wouldn't unlock so after using the key in the drivers door I put the fob in the dash and no sign of life at all, I tried the spare and the same thing happened. So completely dead.

I had a friend with jump leads help he put a meter on the front charging points under the bonnet and no sign of life, we then connected the jump leads and after 10 mins we had got to the battery in the boot and the battery had a good voltage so we started the car and it worked first time all electrics working fine. My friend noted that the charge was high around 14.8v so thought maybe the alternator was putting in too much charge and the battery shut down? Anyway we disconnected everything and so far the car has been OK since, no signs of a low battery all electrics working perfectly. I am just worried its going to die again sometime soon so will be taking it to the specialist Monday morning.

Strange one, or does somebody know what could have caused it. No strange lights in the sky or anything.

MattX · Post by **MattX** » Sat Jun 18, 2016 6:51 pm

Get yourself a multimeter and just keep checking it.
Jumping a flat battery and running it won't recharge it though so I'd expect it to go again sooner rather then later.

applekev · Post by **applekev** » Mon Jun 20, 2016 6:48 pm

Possible the battery is being charged to high when the car is running eg. 14.8-15 volts could that have caused the car to have died?

X5Sport · Post by **X5Sport** » Mon Jun 20, 2016 9:00 pm

When the battery was changed was the car recoded for the new one? If it wasn't then you will have trouble going forward. The E70 has intelligent charging (IBS) and needs to be told when and what type of new battery was installed. If it's wrong then you could indeed be overcharging it. The system modifies the charge cycle as the battery ages.

Batteries don't shut down. They either work, or they don't. No voltage indicates a connection issue as the under bonnet connection is direct off the battery. No fuses (other than the emergency cutter) in the circuit. Hence it being the jump start/charging point.

It will be worth getting to the battery and checking that the connections are properly tightened and not a loose fit. It might be that the intelligent charging connector on the battery +ve lead is about to fail as that will stop the charging.

The charging voltage is determined by the IBS and hence it needs to know the battery type. Not all specialists either know how to, or bother with the coding so it is worth getting that looked at. 14.8V is fine for an AGM type. They can be charged at up to 15.3V subject to air temp. You need to check the battery type.

Mpower · Post by **Mpower** » Mon Jun 20, 2016 11:09 pm

I tend to agree with what X5Sport has said as symptoms of non registering the battery here,but if the OP had used a BMW specialist surely they are aware of this required procedure?

Best to ring them to confirm or since it's a new battery it's their responsibility to sort it out and I would insist a new battery as the current one is probably damaged by overcharging.

X5Sport · Post by **X5Sport** » Tue Jun 21, 2016 2:45 pm

I agree, they should know what they are doing. My local BMW Indy is fine with the saloons but struggles with the X cars - possibly because most clients only bring 3 & 5 series motors in.

Mpower · Post by **Mpower** » Tue Jun 21, 2016 4:26 pm

[quote="X5Sport"]
I agree, they should know what they are doing. My local BMW Indy is fine with the saloons but struggles with the X cars - possibly because most clients only bring 3 & 5 series motors in.
[/quote]

It'll makes me cringe at the thought that a garage calling themselves "specialist" is let loose on my X5 not REALLY fully having the knowledge or experience on these particular models![emoji33]

We are at the mercy of the dealers and specialist establishments.

kjb1 · Post by **kjb1** » Sat Aug 20, 2016 2:28 pm

Buy the carly bmwhat app and code the battery yourself. Its beyond easy!!

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kjb1 · Post by **kjb1** » Sat Aug 20, 2016 2:28 pm

check all earth points also in car

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